As mobile communication units become smaller and lighter, users find it increasingly difficult to input correctly telephone numbers via the ever decreasing in size mobile communication unit keypad. Furthermore, public telephone systems are programmed to automatically recognize specific telephone service codes such as “411” (telephone information), “611” (telephone repair), or the like in the United States, as well as general emergency call numbers such as “911” in the United States or “119” in South Korea, respectively, during telephone input.
As a result, if a user in South Korea were to attempt, for example, to make a telephone call to 011-9876-5432 via a mobile communication unit, by erroneously dialing 119-876-5432, i.e. failing to dial the first “0” digit, the mobile communication unit would automatically ignore the rest of the input digits after “119” and place an unsolicited call to the “119” general emergency call center.
A similar result would occur in the United States, if a user were to dial, for example, by mistake 911-609-2345 instead of 1-911-609-2345. In this case, since the input “911” is not a valid area code, but is a valid general emergency call number, the public telephone system automatically places an unwarranted call to the nearest general emergency call center. If the first three digits after a missed “1” in the United States are not recognized as either a valid area code or a valid emergency call number by the public telephone system, the system is programmed to generate an appropriate input error warning to the user.
No method or system for preventing call errors of this type is known in the prior art.